The BufferTime operator groups the notifications of the source sequence into chunks, where each chunk contains the elements emitted during the specified TimeSpan. The overlap between the elements in each chunk can be controlled using the TimeShift property.

If no TimeShift is provided, the chunks will be strictly non-overlapping, with a new chunk beginning when the previous chunk ends. If TimeShift is smaller than TimeSpan, chunks will be overlapping, with a new buffer created every TimeShift interval. Finally, if TimeShift is larger than TimeSpan, there will be a time gap between each chunk where elements from the source sequence may be dropped.